Calibration Method and Uncertainty Evaluation of 2θ Angle for X-Ray Diffractometer

This paper presents a method of calibrating X-ray diffractometer by using single-crystal silicon powder reference material. The purpose of this method is to calibrate the diffraction angle of X-ray diffractometer and evaluate the uncertainty. In particular, the GUM uncertainty is used to evaluate the propagation rate, and four standard uncertainty components including measurement repeatability, reference material, goniometer and zero position error are considered. In practice, the uncertainty of the result of the measurements is 0.007 degree. It also proves that the calibration method can meet the requirements of conformity assessment.